1. Field of the Invention
The present general inventive concept relates to a media detection apparatus and method usable with an image forming apparatus, and more particularly, to a media detection apparatus and method usable with an image forming apparatus and capable of making print conditions optimal by determining what type of media is used in the image forming apparatus.
2. Description of the Related Art
An image forming apparatus is a device used to output electronic documents or graphic files stored in a host, such as a personal computer, on recording media, such as paper, and is generally classified into a static type image forming apparatus, such as a laser printer, and an inkjet type image forming apparatus, such as an inkjet printer.
The static type image forming apparatus employs a method of applying a developing agent such as toner on a surface of a photosensitive body, at which a static latent image is formed, and then transferring and setting the image on surfaces of the recording media to obtain printed matters. On the other hand, the inkjet type image forming apparatus employs a method of ejecting fine ink droplets to the surfaces of the recording media.
In order to implement high speed and high quality print, the image forming apparatus is capable of reducing a size of an expressible minimum dot and simultaneously printing a large number of dots. That is, precision of expression may be improved by enabling the image forming apparatus to print with smaller dots, and print speed may be increased by simultaneously printing the large number of dots.
Although the printable minimum dot size may be extremely decreased, it may be meaningless in certain recording media. For example, in the case of the inkjet type image forming apparatus, since ink droplets ejected in a small size may be spread and dried at different speeds depending on the type of recording media, the size of the ink droplets ejected from the ink ejection head may not effect the print quality on all types of recording media in the same way. In addition, when a large amount of ink is simultaneously ejected for high-speed printing, print quality may be deteriorated if the ink is not yet absorbed into the recording media. Similar problems may occur in the static type image forming apparatus.
Therefore, in order to perform high speed and high quality printing, it is necessary to vary print conditions depending on the type and characteristics of the recording media, and a device to detect what type of recording media is used to be installed in the image forming apparatus.
FIG. 1 is a schematic view illustrating a conventional media detection apparatus disclosed in U.S. Pat. No. 5,139,339. The conventional media detection apparatus 30 performs operations of irradiating light on a surface of a recording medium 35 moved therein using a light source 31, receiving light totally reflected and diffuse-reflected through two light receiving parts 32 and 33, respectively, and calculating a ratio therebetween, comparing the ratio with a predetermined ratio, and determining the type of the recording medium 35. In this process, the detection apparatus 30 irradiates the light on a plurality of portions of the recording medium 35 in order to improve its precision.
In general, the image forming apparatus uses recording media such as transparency paper, glossy photo paper, paper exclusively used for an inkjet printer, plain paper, and so forth. All of the different recording media have different characteristics, such as surface roughness, gloss, or the like. As a result, the different recording media have a difference between ratios of total reflection and diffuse reflection, thereby allowing the detection apparatus 30 to determine the type of recording media.
However, the detection apparatus 30 often incorrectly detects the type of recording media since surfaces of the recording media do not always maintain a planar state during conveyance of the recording media. That is, when the recording media is bent during conveyance thereof, since the surfaces of the recording media become irregular, the type of recording media may be incorrectly detected due to a difference between the predetermined and detected total reflection and diffuse reflection ratios. In addition, when a mounting angle of the detection apparatus is varied due to long-term use, the same problem may occur.